A neighborhood near the school turned into a triage area for the wounded, and students who ran there spoke of their horrible experience. CNN affiliate reporter Hendrik Sybrandy, of KMGH, reports. (April 21)

LITTLETON, Colorado (CNN) -- After word from the bomb squad that a suburban Denver high school was safe, investigators entered the building on Wednesday to collect evidence and photograph the scene of the rampage that left 15 people dead, including two teen-age suspects.

Agonized parents braced for the worst as bodies remained inside Columbine High School while police scoured the building for potential bombs and booby traps in the aftermath of Tuesday's terror.

"The investigation is under way," Deputy Steve Davis of the Jefferson County Sheriff's Department said at midday on Wednesday. "The bomb team has assured them the building is safe at this point. We don't feel there are any other devices we have to worry about in the building."

Davis said 11 males and four females were killed. One of the males was an adult, "probably" a faculty member, he said. More than 20 people were wounded, some of them critically.

While some of the fatalities and injuries came from gunfire, others were the result of explosions, Davis said.

"It was a combination of both," he told CNN. "We had victims ... that had wounds consistent with shrapnel and consistent with gunshot(s). There were numerous bombs detonated in this school ... during this assault."

Authorities identified Eric Harris, 18, and Dylan Klebold, 17, both juniors at Columbine, as the two gunmen wearing black trench coats who laughed and hooted as they opened fire on classmates with "long rifles and handguns" and set off explosions before killing themselves.

In addition to unexploded bombs found inside the school, other explosive devices were located in the suspects' cars and bomb-making material was found at Harris' home, police said.

Some of the explosives were on timers, Davis said. The bombs were "easily made and most of the components can be purchased at any hardware store," he said, without identifying the materials.

Davis said a computer was seized from the home of one suspect, but did not know if the suspects used the Internet to obtain bomb-making instructions.

Authorities confiscated a computer and other materials from Harris' home

Hinkle says many of the victims inside the high school are not carrying identification

Identifying the victims and removing the bodies could take time, said Sgt. George Hinkle, a police SWAT team officer from Lakewood, Colorado, who has been inside the school. "A lot of them aren't carrying ID."

"We want to make sure the scene is fully preserved for court purposes, in case it turns out there are other suspects and court cases that may occur later down the road," said Hinkle.
"Everything has to be photographed, diagrammed and the identities established before people are moved."

He said there were at least "five or six" explosions inside the school, while fire sprinklers set off by the blasts left heavy water damage. "We've got all the debris that goes with a scene like this. We've got backpacks all over. We've got shoes (and) spent shell casings. It just looks like a war zone," Hinkle said.

Students streamed into Clement Park next to the school on Wednesday morning to leave flowers and share their feelings about the shootings. "This was out of the blue. Nobody expected it," student Katie Crena told CNN.

She and some of her fellow students locked themselves into a classroom after the violence began. "I thought, 'This is it, I'm going to die,'" Crena said.

"I mean they were so close. They shot the window of the classroom next door. They tried to get... into our classroom. They were playing with the handle and then went on. We could hear people pleading for their lives," she said.

At the White House, President Clinton praised the quick thinking of police and the courage of students and teachers who rushed to protect each other.

Clinton also said children all over America need to be reassured of their safety. "We also have to take this moment once again to hammer home to all the children of America that violence is wrong," the president said Wednesday.

"And parents should take this moment to ask what else they can do to shield our children from violent images and experiences that warp young perceptions and obscure the consequences of violence -- to show our children by the power of our own example how to resolve conflicts peacefully."

Police help an injured student escape on Tuesday

Attorney General Janet Reno said she may push to have more counselors in the nation's schools to avoid problems before they start.

The country must "make investments in counselors and support systems that can help us identify children who are on the verge of terror and help take steps to alleviate the problem before it produces tragedy such as this," she told CNN from Minneapolis.

The attack began when Harris and Klebold, wearing fatigues and ankle-length black coats, opened fire in the school parking lot around 11:30 a.m. Tuesday before entering the school cafeteria.

Police said they exchanged shots with officers and were later found dead in the school library with self-inflicted gunshot wounds and bombs around their bodies. "It appears to be a suicide mission," Jefferson County Sheriff John Stone said.

No suicide note has been found, authorities said.

Reno says she may push for more counselors in schools across the nation

Davis said he did not know how the heavily armed pair obtained their weapons. It must have taken "quite a bit of planning to carry that much equipment and ammunition (into the school)," he said.

He said Harris and Klebold were the only suspects, so far. "If, later, our investigation shows that other people were involved in either the planning or the execution of this incident, then certainly we would charge them."

After the four-hour siege ended, police originally said that as many as 25 people may have been killed. By Wednesday morning they revised the estimated death toll downward to 15.

Four people who knew the suspects, some of them former students, were questioned in the case and released, police said.

Many stunned students, parents and residents of Littleton, an affluent Denver suburb, attended a memorial service Tuesday night, and school officials were arranging crisis counseling for teens struggling to cope with the massacre, the most recent of several school shootings nationwide.

While police have not given a motive, several students said Harris and Klebold were members of a group calling itself the "Trenchcoat Mafia," outcasts who bragged about guns and bombs and hated blacks and Hispanics, as well as student athletes.

Police aid a victim in Tuesday's shooting at Columbine High School

With the exception of one African-American, all of the fatalities were white, Davis said.

Students said the "Trenchcoat Mafia" was fascinated with World War II and the Nazis and noted that Tuesday was Adolf Hitler's birthday.

Members of the group don't talk much to other students and "give people dirty looks," student Josh Nielsen told CNN.

The attackers marched into the library of Columbine High School with guns and pipe bombs, demanding that "all jocks stand up. We're going to kill every one of you," said student Aaron Cohn.

A gunman looked under a desk in the library and said "Peek-a-boo," then fired, Cohn said. Anyone who cried or moaned was shot again. One girl begged for her life, but a gunshot ended her cries, the student said.

Cohn said one killer put a pistol to his head but did not shoot him. Instead, he said, the shooter turned his attention to a black student, saying, "I hate niggers." Cohn heard three shots but couldn't see what happened.

"You could hear them laughing and running upstairs," said one student, who broke down in tears as she recounted the killing spree. "They didn't care who it was and it was all at close range."